Using a power steering pump for hydraulics

[brandoro]

A millwright welder I worked with a few years ago had built himself a little garden tractor mostly out of junk. I suspect he just wanted to see if he could. His hydraulics were powered with a power steering pump off an old car. I never saw it so can't say how he did it but in conversation it sounded like he had managed to get the power steering pump to operate cylinders and a small hydraulic motor.

By the way, if you fill out your profile so we know what kind of machine you have we will be better able to answer your question(s).

 

[RickB]

Its easy to say " it wont work" how about saying how it might possibly work?

I have a clear understanding of open center hydraulic systems. Adding a T to a pump output line and supplying two open center valves does not work. It isn't a maybe/maybe not situation. At a minimum you need the valves plumbed in series, and the first needs to have power beyiond flow feeding the second. If an actual steering system is involved, that needs to have priority flow.

I am not taking exception to using a P/S pump, I have a huge problem with the way you are proposing to plumb the system. If it is slow or weak that is one thing. If it is non functional, or compromises steering control and/or components, that's entirely another.

 

[GT2]

Please school me if I'm wrong.
The saginaw "TC" pump and auto steering gear I'm using are not open center style.
The pump flows as long as there is a demand and then goes into internal by-pass.
If the pump is in by-pass why cant I use that flow for something else?
I would think that at worst I would have redused assist if using two things at once?
Pirate4x4.Com - Extreme Four Wheel Drive
Click and scroll down to read about sagunaw pumps.

PS, Im not married to this idea, I could always run two pumps.

 

[J_J]

Please school me if I'm wrong.
The saginaw "TC" pump and auto steering gear I'm using are not open center style.
The pump flows as long as there is a demand and then goes into internal by-pass.
If the pump is in by-pass why cant I use that flow for something else?
I would think that at worst I would have redused assist if using two things at once?
Pirate4x4.Com - Extreme Four Wheel Drive
Click and scroll down to read about sagunaw pumps.

PS, Im not married to this idea, I could always run two pumps.

Maybe you can,. The steering system on the Power-Trac, uses the hydraulic fluid from a pump, to steer only if the steering wheel is turned. The fluid goes through the pump via a priority circuit, and feeds the lift and tilt cylinders, If you try and steer at the same time, the lift force will diminish. On the PS pump, when you are bypassing, I would assume that the fluid is going back to tank. If you interrupt the flow, with a valve, then the valve might operate a cylinder or whatever. Just hook it up and test your theory.

 

[ray66v]

I used a GM p/s pump many years ago, to run a small cylinder on my lawn tractor. The cylinder was a steering cylinder off a Ford granada.

Though the pump had about a 6 inch pulley, it put out so much fluid, I had trouble slowing it down enough to keep it from over heating. I was finally able to drive it slow enough with a 1.5 inch diameter pulley on the engine.

At an idle, you could see the writing on the belt, as it turned. Yet, it would still operate the cylinder with enough power to pick up a 100lb snow blower, with a 160lb man sitting on it.

 

[RickB]

Please school me if I'm wrong.
The saginaw "TC" pump and auto steering gear I'm using are not open center style.
The pump flows as long as there is a demand and then goes into internal by-pass.
If the pump is in by-pass why cant I use that flow for something else?
I would think that at worst I would have redused assist if using two things at once?
Pirate4x4.Com - Extreme Four Wheel Drive
Click and scroll down to read about sagunaw pumps.

PS, Im not married to this idea, I could always run two pumps.

The more info you give upfront, the better info you get in return.
You didn't specify any pump, valve, or cylinder application.
Garbage in, garbage out.

 

[GT2]

The more info you give upfront, the better info you get in return.
You didn't specify any pump, valve, or cylinder application.
Garbage in, garbage out.

You know... there is no excuse for your attitude!
As a so called "expert" you should have known a steering pump self relieves.

 

[Egon]

I am assuming you are talking about adding an automotive power steering pump that operates recirculating ball power steering system that requires around 3 gallon a minute to function properly.

Some of the small HST tractors with loaders are operating with pump capacity of just a little over 3 gallons a minute I do believe.

It should be easy to look at some statistics for tractors to give you a real good idea.

 

[mwb]

You know... there is no excuse for your attitude!
As a so called "expert" you should have known a steering pump self relieves.

I am not throwing gas on a small fire here but I don't think a PS pump does this. The pump has a pressure relief valve but it is the steering gear / rack that does the open center part. The PS pump is of a fixed displacement, it requires an open center system or the relief valve will open and squeel.

PS pumps can be used for other applications; check out Mile Marker winches for example - they offer accessory hose kits to attach their gear in series with the power steering system.

 

[Olmike]

Around here back in the late 70's,rear mounted bale spears were just comin on.There were alot of farmers plumbing in a single spool valve between the PS pump and the steering gear.They all worked ok but I think the DOT would probably frown on that now. Mike